Interlocking control apparatus



June 22, I c w BELL INTE RLOCKING CONTROL APPARATUS Filed March 19, 1935 5 Sheets-Sheet 1 m INVENTOR k EE flww M Q m um Charles WBell BY HIS ATTORNEY Z mxfi Gan wk QN w NN QNN fi NH 3 A. Q NWM AN 3 W TUV N June 22, 1937. c. w. BELL INTERLOCKING CONTROL APPARATUS 3 Sheets-Sheet 3 Filed March 19, 1935 NW mm a AR INVENTOR (711111165 W Bell. Q/Rf [US ATTORNEY Patented June 22, 1937 2,084,425 INTERLOCKING CONTROL APPARATUS Application March 19, 1935, Serial No. 11,807

I 35 Claims.

My invention relates to interlocking control apparatus, and is particularly adapted for, though not limited to, apparatus for controlling railway track switches and signals in a railway switching or interlocking layout.

One feature of my invention is the provision of novel and improved group releasing means for a plurality of devices such, for example, as signal lever looks or looking relays for a plurality of railway track switches.

I will describe four forms of apparatus embodying my invention, and will then point out the novel features thereof in claims. I

In the accompanying drawings, Figs. 1 and 2 are diagrammatic views showing one form of apparatus embodying my invention. Fig. 2 is a diagrammatic View showing a modification of the arrangement of Fig. 2. Figs. 3, 4, 5, 6 and '7 are diagrammatic views showing a third form of 0 apparatus, also embodying my invention. A fourth form of apparatus embodying my inven tion comprises a combination of the parts shown in Figs. 2 3, 4, 5 and 6.

Similar reference characters refer to similar parts in each of the views.

Referring first to Fig. 1, railway tracks designated by the reference characters X, Y and Z, respectively, are shown interconnected by switches W W and W The reference characters I and l designate the rails of track Z, and the reference characters 2 and 2- designate the rails of track Y.

These rails are divided by insulated joints 3 to form a plurality of track sections w-b, b-c,

de, and e-f. Each track section in which a switch is located will be referred to hereinafter as a detector section. Track sections ab and. e-f in the rear of signals S and. S respectively, will be referred to as approach track sections.

Each of the track sections is supplied with current by a battery l connected across the rails adjacent one end of the section. A track relay, designated by the reference character T with a distinguishing exponent, is connected across the 5 rails adjacent the opposite end of each track section.

Reference character S with distinguishing exponents designates signals which are placed adjacent points I), c, d and e, and which. as here shown, are of the semaphore type, but which may be of any other suitable type. Signals S and S are mounted on a common masti5, and. signals S and S are mounted on a common mast 6. Signals S S and S govern eastbound ,55 traflic movements, that is, movements which are made over the stretch of tracks from left to right as shown in the drawings, and signals S S S and S govern westbound trafiic movements, that is, movements which are made over the stretch of tracks from right to left as shown in the drawings.

Each switch W is operated by a mechanism which may be an electric motor or any other suitable device, designated by the reference char acter 10 with an exponent corresponding with that of the reference character W for the switch. Mechanism w for operating switch W is shown. controlled by pole-changing contacts l and 8 of a manually operable switch lever W, and

also by a normally closed contact 9 ofswitch W and by normally closed contacts lo H and I2 of manually operable signal levers V V and V respectively. Mechanism w is controlled by pole-changing contacts l and 8 of manually operable switch lever V and by normally closed contacts l3, l4 and E5 of levers V i V and V respectively. Mechanism wl may be. controlled similarly to mechanisms w and w or it may be controlled in multiple with mechanism w The switch and signal levers V may be mechanically interlocked. 'If they are mechanically interlocked, the normally closed contacts of the signal levers can be omitted from the control circuits for the switch operating mechanisms 11).

Each of the switch levers V and 'V has a normal position 11. and a reverse position v. pole-changing contacts 7 and 8 of each of these levers close a normally energized circuit for the associated mechanism in when the corresponding lever V is in its n position, and close a reverse energizing circuit for the associated. mechanism to when the corresponding lever V is in the 1 position.

Each of the signal levers V V and. V has a normal position N, a reverse position L to the left as shown in the drawings, a normal lock or indication position B to the left, a reverse position R to the right, and a normal lock or indication position D to the right. Lever V operates seven contacts, namely, contact Hl in the circuits for mechanism w contacts i3, 47, 54 and 56 shown adjacent the representation of lever V and contacts Gi and in the circuits for time element relay TE of Fig. 2. Lever V operates seven contacts, namely, contact I W in the circuits for mechanism w contacts l4, 3!, 38 and 42 shown adjacent the representation oflever V and contacts and 65 in the circuits for time element relay TE of Fig. 2.

The

Lever V operates five contacts, namely, contact l2 in the circuits for mechanism wcontacts IS, IT and 2t shown adjacent the representation of lever V and contact 64 in the circuit for time element relay TE of Fig. 2.

Adjacent the symbol for each of the contacts of signal levers V a reference character is placed to designate the position or positions of the as sociated lever at which each of these contacts is closed. For example, the letter N adjacent contact l5 of lever V means that contact [5 is closed when lever V is in its N position only; letter L adjacent contact ll of lever V means that contact l! is closed only when the lever is in its reverse position L; the letter B adjacent contact of lever V means that contact 20 is closed only when lever V is in the B position; letter L to the left and letter Rto the right of contact 3| of lever V mean that contact 3| is closed only when lever V 5 is in its L position or'its R popositions. I

Each signal lever V can be returned to its N position from either its L or its R position only when an associated electric lock is energized.

Each'of these electric locks is designated by the reference character K with an exponent corresponding to that of its lever. Each electric lock K comprises a control winding 21, a segment'3l), and a locking dog 28 which is controlledby Winding 2?. Segment 'is provided with a lug 29. Each segment 30 is mechanically connected with its lever V, as indicated in the drawings by the dash lines. One manner of connecting each segment 30 with its lever V is such that when the associated lever V is moved to the left, the segment 30 will be moved to. the right, or if the lever V is moved to the right, the segment 3|! will be moved to the left. If, when any one of the signal levers V is moved to either 'of its reverse positions L and R, the winding 21 of the associated electric lock K becomes deenergized, the dog 28 controlled by that winding 21 will rest on its segment 30, and if then an attempt is made to return the lever to its N position, dog 28 will engage'lug 29 when the lever reaches its position B or D, and will thus prevent complete return of the lever to its N. position until the associated winding 21 is again energized. f 1.

Each signal S is controlled by. a signal relay which is'designated by the reference character H with an exponent which corresponds with the exponent of its signal. Each relay H is controlled by one of the signal levers V in one of its reverse positions, and by other conditions such, for example, as the positions of the switches in the route over which trafiic is governed by the corresponding signal. For example, a route relay A which controlsrelay H in part is shownscontrolled by a circuit which is controlled in part by switch W and which is closed only when switch W is in its reverse position. Relay A may also be controlled by switches W and W Each of the other relays A may be similarly energized only when each switch in an associated route is in the position required for that route. Each of the relays H is controlled by a corresponding routeT'elay A, and hence each relay H is energized only when the switches of a corresponding route are in the position required for the route.

Winding 2'! of each electric lock K is energiz able under given traffic conditions only when its lever is in one of its lock or indication positions B and D.

A selector relay, or release stick relay E is provided for each signal lever V, and one time element relay TE, shown in Fig. 2, is provided for all the signal levers V. By -means of time element relay TE and each stick relay E, an associated electric'lock K can be energized upon the lapse of a measured period of time after an associated relay H is de'energized by movement of an associated signal lever V to one of its lock positions B and D. Relay TE is so constructed that, upon becoming energized, a measured interval of time must elapse before its front contacts will close, but upon becoming deenergized, its back contacts will quickly close.

Time element relay TE is energizable under given traffic conditions only when one of the le- Vers V is in its reverse lock position B or D. When relay TE is energized, it may at anytime be deenergized if one of the manually operable push button circuit controllers v, is opened. A push button circuit controller '0 may be provided for each signal lever V, as shown in the drawings, and may be distinguished by an exponent cor responding to that of the associated lever V.

A repeater relay, designated by the reference character P, is shown energized in Fig. 2, whenever relay TE is in its deenergized condition. An indicator, here shown as an electric lamp is controlled by a front contact of relayP.

In each of the drawings, the contacts operated by the various relays or by the levers V are identified by numbers, such. numbers having distinguishing exponents when the contacts are shown elsewhere than adjacent the representa- The exponent for each of these v:contact numbers comprises the reference character and exponent for therespectiverelay'or lever. For

, example, the exponent-T3 for contactll' in'the pick-uplcircuit for winding 21 of lock K inFig. 1 comprises the reference character'T and its exponent 3-for track relay T which operatescontact 2 F. Similarly, the exponent V for contact tion of the relay or lever by which they are operated.

54 in one'of the circuits shown for relayTE in Fig. 2 comprisesthe reference character V and its exponent 3 for signal lever V which operates contact 64 V r 1 a Fig. 2 is the same as Fig. 2 except that relay TE is here controlled by. only the push button circuit controllers c, and is therefore normally.

energized, whereas in Fig. 2 it, is normally de energized. With relay TE controlled as'shown in Fig. 2 relay P and indicator '2' are normally deenergized, whereas with relay TE normally deenergized as shown in Fig. 2, relay P and indicator i are normally energized.

In the first and second forms of apparatus,

M shown in Fig- 6, are used instead of the signal lever locks K shown in Fig. 1; the slow-release relays F, one for' each relay M, are used instead of relaysE shown in Fig. 1; the switch mechanisms ware controlled, in part, by front contacts of relays M, as shown in Fig. 3, instead of by normally closed contacts of the signal levers; and

the track and signal layout is as shown in Fig. l,

but the control of the switches and signals is modified as shown in Figs. 3, 4 and 5.

In Fig. 4, signal relays H are shown controlled by non-locked levers, and in Fig. 5, auxiliary signal relays h are shown controlled by relays H. Circuits are shown in Fig. 5 for only relays h h 7L and 71 The circuits for relays 7L hi and h are similar to those shown for relays 11,

h h and are, therefore, omitted from the drawings.

Time element relay TE is shown normally energized, in Fig. '7, through front contacts of locking relays M.

Having described, in general, the arrangement of various forms of apparatus embodying my invention, I will now trace in detail the operation of these forms of apparatus.

As shown in the drawings, all parts arein the normal condition, that is, each track relay T is energized; each switch and signal lever V, and each push button circuit controller contact 12 is in its normal position; each switch W is in the normal position; each signal S is indicating stop; some of the route relays A are energized, and

others are deenergized; relay P and indicator 2' are energized in Fig. 2, but are deenergized in Figs. 2 and 7; relay TE is energized in Figs. 2 and 7, but is deenergized in Fig. 2; relays M and switch mechanisms w are energized; and lock magnets 2? and relays E, H, h and F are deenergized.

I will first trace the operation of the first form of apparatus, shown in Figs. 1 and 2.

With the switch and signal levers V in their normal positions, normal control circuits are closed for switch mechanisms w. The circuit for mechanism 11) passes from terminal :2 of a suitable source of current not shown in the drawings, through contact I of lever V in its 11 position, contacts l3, i l and it; of levers V V and V respectively, in their N positions, mechanism w i5 and contact 8 of lever V in its n position to terminal 0 of the same source of current. A

similar circuit is closed for mechanism w passing from terminal :2, through contact I of lever V in its is position, contacts W HE and i2, mechanism w and contact 8 of lever V back to terminal 0. A branch path for this circuit is also closed through contact 9 which is operated in conjunction with mechanism m and which is closed only when switch W is in the normal position.

With relay TE deenergized, a circuit is closed for relay P including back contact 63 of relay TF. With relay P thus energized, indicator 1' is energized by a circuit which includes front 60 contact 59 of relay P.

I will assume that the leverman, in order to clear signal S moves lever V to its R position, thereby completing a circuit for relay H passing from terminal as, through contact ll of lever I "VP- in the R position, contact 48 of route relay A and the winding of relay I-I to terminal 0.

Relay H upon becoming energized, completes a circuit for signal S, passing from terminal .1,

through contact 53 and the mechanism of sig- TQ nal S to terminal 0, thereby causing the arm of signal S to be operated to the proceed position.

If the leverman should decide to return signal S to its stop position before a train arrives on approach section ab, he will return lever V to 7 its D position, thereby completing an energizing circuit for lock K passing from terminal IL, through contacts 5|, 52 and 53 of relays H H and H respectively, contact 54 of lever V in the D position, contact 55 contact 56 of lever V in the D position, and winding 21 of lock K to terminal 0. Winding 2i, upon becoming energized, closes its contact 51, thereby completing its own'stick circuit which is the same as the pick-up circuit previously traced except that it includes contact 5'! instead of contacts 55 and 56. Winding 2i will therefore be retained-in the energized condition, irrespective of the condition of track relay T as long as lever V is left in the D position. Winding 27 of lock K Z upon becomingenergized, also removes dog 28 from engagement with lug 29 of segment 313 of lever V and hence the leverman can complete the return of lever V to its N position. Lever V when moved to its D position as just described, closes its contact SW in one of the circuits for relay TE, but contact GS is open if no train is in section Ctb, and hence relay TE does not become energized.

I will assume that after lever V is returned to its position N, the leverman again desires to clear signal S and therefore again moves lever V to its R position. I will also assume that an eastbound train arrives in section wb', and then passes signal S into section 'b*c, thereby deenergizing relay T It now the leverman returns lever V to the reverse lock position D, a second pick-up circuit will be closed for winding 27 of lock K which is the same as the first pick-up circuit as far as contact 54 of lever V and thence passes through contact 58, and winding 27 of lock K to terminal 0. Lever V can now be returned to its N position irrespective of whether contact 55 in the first pick-up circuit is open on account of part of the train reaching back into sec-. tion a-b, or on account of a second train having entered section ab.

I will next assume that after lever V has been returned to its N position, the leverman again clears signal S by moving lever V to its R position, and that after a train enters approach section 00-2), but before it has reached signal S, the leverman returns signal S to the stop position by moving lever V away from the R position. When lever V reaches the D position, the pick-up circuit first traced for winding 2'! of lock K will be open at contact 55 on account of re lay T being deenergized due to the presence of the train in section ab, and the second pick-up circuit previously traced will be open at contact 53' on account of detector section b-c being unoccupied. Lever V will therefore be held in its D position by engagement of its dog 28 with lug 29 of its segment 39.

A circuit will now be completed for time element relay TE, passing from terminal :13, through contacts 'lifi 66", 6'5", 0 c and 11 and the winding of relay TE. to terminal 0. At the same time that this circuit for relay TE is completed, a circuit is also completed for release relay E which is the sameas the first pick-up circuit for lock K as far as contact 5 5 of lever V and thence passes through contact 5?, and the winding of relay E to terminal-o. Relay E upon becoming energized, completes its stick circuit which is the same as the pick-up circuit just traced, except including contact 6d of relay E instead of contact 59 As soon as relay TE becomes energized, its contact 68 will be opened, causing relay P to be to terminal 0.

deenergized and to, in turn, deenergize indicator 2' by theopening of contact 69. When relay IE has been energized for a measured period of time, its front contacts will close, and hence a third pickup circuit will be completed for magnet 2'! of lock K which is the same as thefirst pick-up circuit as far as. contact 5% of iever V thence passing through contacts fil and GZ and winding 2? to terminal 0.

The leverman can now complete the return of lever V to its N position.

I will assume that all parts of the apparatus are again in their normal condition, and that the leverman then clears signal S by moving lever V to its R position, as previously described.

I will also assume that the leverman desires to arrange for a traffic movement from track X over switch W reversed and switch W normal. He will therefore move switch. lever V to its 1 position, causing the pole-changing contacts l and 8 of lever V to be closed in the r po sition. With pole-changing contacts l and closed in the r position, current of re? verse polarity will be supplied to the circuit previously traced for mechanism W2, causing this mechanism to move switch W to its reverse position. With switch W in its reverse position, contact l6 operated in conjunction with switch W will complete the circuit for route relay A only a portion of which is shown in the drawings. Relay A will therefore be energized, and will hence close its contact I8. The leverman will now move lever V to its L position, thereby completing a circuit for energizing relay H this circuit passing from terminal at, through contact ll of lever V contact it of relay A and the winding of relay H to terminal 0. Relay H upon becoming energized, completes a circuit through its front contact 63 for operating the mechanism of signal S to the clear position.

I will further assume that an eastbound train arrives on approach section ab while signal S is in the clear position. I will also assume that the leverman returns signal S to the stop position before the train reaches this signal, by returning lever V to its D position Where further movement of the lever will be arrested by engagement of dog 28 of lock K with lug 29 of segment 35 of lever V Relay E will now be energized by its circuit previously traced, and relay TE will also be energized by the circuit previously traced through contact 65 Relay TE will therefore be set into operation.

I will now assume that the leverman decidesto return signal S to the stop position, and to release lever V as soon as possible. He will there fore return lever V as far as its B position, and will momentarily open the circuit for relay TE by depressing push button contact 22 thereby returning relay TE to the deenergized condition, to complete a circuit for relay E As soon as he permits contact 12 to again close, relay TE will be again set into operation. Another circuit for relay TE is now closed, in addition to the circuit through contact 65 The additional circuit passes from terminal x, throughcontactsfit 6T, 0 1: and 12 and thewincling of relay With lever V still in the D position, relay E is still energized by its stick circuit. The return of lever V to its B position has completed a circuit'for relay E passing from terminal at, through contact IQ of relay H contact 28 of lever V contact .23 and the winding of relay E to terminal 0. Relay E will therefore become energized and. complete its stick circuit which is the same as the pick-up circu'itjust traced except that it includes contact 24 of relay E instead of contact 23 As soon as relay TE closes its front contacts, lock K will become energized by the circuit previously traced through contact 62TE, and lock K will become energized by a circuitpassing from terminal as, through contact [9 of relay H contact 20 of lever V contacts 253 and ZE and winding 21 of lock K to terminal 0. The leverman 'can' now return both levers V and V to the N position.

From the foregoing description of the operation of the first form of apparatus embodying my invention, it follows that time element relay TE is normally deenergized, and that in order to set relay TE into operation to release only one lever, the leverman has only to return that one lever to its lock position, no other manual operation, such as that for opening a push button contact '0, being necessary. With relay TE normally deenergized, relay P and indicator 1 are normally energized. In order to start the release of a second lever before the releaseof a first lever is completed, the leverman will deenergize relay TE by momentarily opening one of the contacts 1), thereby causing the operation of relay TE to start over.

The second form of apparatus is the same as the first form except that in the control of relay TE the multiple'paths shown to the left of push button contact 11 in Fig. 2 are omitted as shown in Fig. 2 Relay TE is'therefore normally energizechand must be momentarily deenergized by opening of one of the contacts 0 in order to be set into operation whenever any lever V is to be released. 7

Assuming, for example, that signal S has been cleared as previously described, and that, when an eastbound train arrives in approach section ab, the leverman decides to arrange some other route. He will thcrefone return lever V to its lock position D, and will then momentarily 1 depress contact c shown in Fig. 21 to deenergize relay TE. As soon as contact o is closed, relay TE will be set into operation to again'close its front contacts. Contact 68 of relay TE will close as soon as contact 22 opens the circuit for relay TE, and hence relay P will become energized, thereby completing the circuit previously traced for relay E Upon the lapse of a measured period of time after the re-energization of relay TE, winding 21 of lock Ki will become energized by its. circuit previously traced, and the levermancan then return lever V to its N position.

I will now trace the operation of the third form of apparatus embodying my invention. With the switch levers V in. the normal position, and with lock relays M of Fig. 6 energized, normal control circuits are closed for switch mechanisms w as shown'in Fig. 3. The circuit for mechanism w for example, passes from terminal as, through contact l of lever V inv the n position, contacts 15 16 and mechanism. w and contact 8 of lever V in the left-hand position, back to terminal 0.

Each of the lock relays M is energized by a stick circuit which includes one of its own front contacts. The stick circuit for relay M for example, passes from terminal m, through contacts lla lil 2 lls contact H5 of relay M and the winding of relay M to terminal 0. A pick-up circuit is also closed for each of the approach locking relays M and M The example, is the same as the stick circuit just traced except that it includes contact 4 instead of contact H5 of relay M Relay TE, shown in Fig. 7, is energized by a circuit passing from terminal ac, through the front points of contacts l52 51 l6l I65 and H, and the winding of relay TE to terminal 0.

I will assume that the leverman clears signal S by moving lever V shown in Fig. 4, to its R position. With lever V in its R position, signal relay H shown in Fig. 4, will be energized by a circuit passing from terminal cc, through contact 41 of lever V in the R position, contact 43 of relay A and the winding of relay 1-1 to terminal a 0. Relay H upon becoming energized, opens its contact I 3 thereby deenergizing approach locking relay M With relay M deenergized, the circuits for mechanisms w for the switches in the route governed by signal S, and also for some switches in conflicting routes, will open, and

ence no operation of these switches can take place. For example, the circuit for mechanism W for switch W of a conflicting route will be open at contact Tl With relay H energized, and with relay M deenergized, relay TE is retained in the energized condition by a circuit which is the same as the circuit previously traced for this relay except that it includes contact 153 and the back point of contact I52 instead cf the front point of contact 52 Relay H upon becoming energized, also closes its contact (ti thereby completing a circuit for energizing relay h this circuit passing from terminal at, through contacts 83 and M and the winding of relay h to terminal 0. Relay it, upon becoming energized, opens its contact H i in the circuit for relay M which is, however, already open at contact ti With relay h energized, a circuit including a contact 160 similar to the circuit shown for signal S will be closed for operating the arm of signal S to the clear position.

I will assume that the leverman desires to return the arm of signal S to the stop position before a train arrives on approach section ah. He will therefore return lever V to its N position, thereby deenergizing relays H and h The arm of signal S will therefore be returned to the stop position, and the pick-up circuit previously traced for relay M will be completed. Relay M will now again close its, contact l52 at the front point. The apparatus can be so arranged that the interval of time between the opening of contact I53 and the closing of contact l52 at the front point will not be surficient to cause relay TE to be deenergized and then set into operation.

I will assume that the leverman, after all parts of the apparatus have been again returned to the normal condition, again clears signal S An eastbound train, upon entering section a-h and then passing signal S, will complete a third circuit for relay TE, which is the same as the first circuit traced for this relay except that it includes contact [55 and the back point of contact i52 instead of the front point of contact i52 Relay TE will therefore be retained in the energized condition by this third circuit. If the leverman returns lever V to the N position while the train is in the detector section bc, approach locking relay M will become energized by a second pick-up circuit which is the same as the pick-up circuit previously traced except that it includes contact 6 instead of contact 4 I will now assume that, after all parts of the apparatus have again been returned to the normal condition, the leverman again clears signal S as before. I will also assume that after a train has entered approach section a+-b, but before it has passed signal S the leverman returns lever V to the N position. With a train occupying section a b, contact ll 4 in the first pick-up circuit for relay M will be open, and with the detector section unoccupied, the second pick-up rcuit for relay M will be open at contact I I6.

Wit? relay M thus deenergized, and with relay H deenergized while contact l55 is open, relay TE will become deenergized, thereupon completing a circuit through its contact 68 for energizing relay. P. With relay P energized, a. pick-up circuit will be closed for energizing release relay F this circuit passing from terminal at, through contacts IIO lll H2 3 9 and l2ll and the winding of relay F to terminal '0. Relay F upon becoming energized by the circuit just traced, completes its own stick circuit which is the same as the pick-up circuit except that it includes contact l2l of relay F instead of contact I20 With relay F energized, relay TE will be set into operation by a, circuit Which is the same as the circuit first traced for this relay except that it includes contact I56 and the back point of contact 32 instead of the front point of contact i52 When relay TE has been in operation for a measured period of time, contact I II will close, and will thereby complete a third pickup circuit for relay M which is the same as the first pick-up circuit traced for this relay except that it includes contacts II'I and H8 instead of contact H4 T With relay M energized, the control circuits for the switches in the route governed by signal S, or in conflicting routes, will be closed. For example, the circuit for mechanism w for switch W will now be closed at contact Ti which was open when relay M was deenergized.

I will next assume that all parts of the apparatus are again returned to the normal condition, and that the leverman then again clears signal S as previously described.

I will also assume that he reverses switch W To do this, he will move lever V to its r position, thereby supplying current of reverse polarity to the circuit for mechanism w on account of polechanging contacts 1 and 8 of lever V being moved to the 1- position. Relay A will therefore become energized.

The leverman will clear signal S by moving lever V to its L position, thereby completing the circuit shown in Fig. 4 for relay H this circuit passing from terminal as, through contact I! of lever V contact l8 of relay A and the winding of relay H to terminal 0. Relay H upon becoming energized, opens its contact I22 in the circuits for relay M causing relay M to become deenergized. With relay I-I energized, and with relay M deenergized, relay TE will be retained in the energized condition by a circuit passing through contact I62 and the back point of contact Ifil instead of the front point of contact ltl in one of the circuits previously traced for relay TE.

7 I will further assume that an eastbound train enters section a b, and that the leverman returns lever V to the N position before the train reaches. signal S. Operation of time element passes the corresponding signal.

relay TE will therefore be started by the circuit which includes contact I 56 and the back point of contact l52 I will also assume that before relay TE has closed its front contacts, the leverman returns signal S to the stop'position by moving lever V to its N position. With relay H now deenergized,

relay TE will be deenergized because of the opening of contact 52 With relay TE deenergized, relay P will become energized by its circuit through contact 68 of relay TE, relay P thereby completing a circuit for relay F passing from terminal 9:, through contacts I22 523 i28 and i29 and the winding of relay F to terminal 0. Relay F upon becoming energized, completes its stick circuit which is the same as the pick-up circuit just traced except including its own contact I30 instead of contact I29 Relay F upon becoming energized, completes another circuit for relay 'I'E, which includes contact I64 and the back point of contact Hil -When relay TE has been in operation for a measured period of time, the front contacts of relay TE will become closed. Relay M will therefore become energized by its pick-up circuit previously traced through contacts H'I and l IB and relay M will become energized by a circuit passing from terminal 3;, through contacts IZZ I23, IZG and I21, and the winding of relay M to terminal 0.

From the foregoing description of the operation of the third form of apparatus embodying my invention, it follows that relay TE is normally energized, and that it is retained in the energized condition at all times except when a.

signal I is returned to the stop position while a train is approaching this signal in section orb, or when a signal i is returned to the stop position while a train is approaching in section eor when any one of the signals S S and S with which no approach locking is associated, is returned to the stop position before atrain In order to set relay TE into operation to release any one of the locking relays M, the levernian has only to return an associated signal lever to its N position, no other manual operation being necessary. If relay TE is already in operation for picking up another relay lVi when the leverman desires to pick up a second relay M, he has only to return the lever associated with the second relay M to its normal position, thereby stopping the operation of the relay TE, and then starting another operation of this relay. Upon completion of the new operation 'of relay TE, both relays M will be picked up. With relay TE energized, relay P and indicator 2' will be deenergized.

The fourth form of apparatus embodying my invention is the same as the third form except that the circuit arrangement of Fig. 2 is used instead ofthat of Fig. 7.- Therefore, whenever any one of therelease relays F is to be energized for picking up a corresponding lock relay M, the

After the deener'gi'zation of relay Til, the cor're sponding relay F will become energized as previously described. Upon the lapse of a measured period of time, during which relay TE is in operation, relay M will become energized by its circuit through contacts H'I and H8, as pro-V viously described.

I have described, for a few typical traiiic movements, the operation of each of four forms of apparatus embodying my invention. From those descriptions of operation, and from the preceding general description, operation of each of the four forms of apparatus for every other possible traffic movement will be readily understood by reference to the drawings. 1

In conclusion, with the first form of apparatus embodying my invention for group'releasing means for signal lever locks or for locking relays, only the usual manual operation of a signal lever is required for setting time element means into operationfor releasing any one signal lever lock or looking relay. If it is necessary to interrupt the operation of the time element means in order to prepare for releasing a second signal lever lock or looking relay, a push button contact u must be operated in addition to the operation of the signal lever.

With the second and fourth forms of apparatus embodying my invention, manual operation of a push button contact o is required in addition to nal lever is required to set a time element relay TE into operation for releasing one or more sig nal lever looks or locking relays.

Although I have herein shown and described only four forms of interlocking control apparatus embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. In combination, a railway track switch, a signal for governing trafiic movements over said switch, manually controllable means for operating said switch, a manually operable signal lever having a normal and a reverse position and also a' normal indication position, means controlled by said lever in its reverse position for clearing said signal to permit a trafilc movement over said switch, means controlled by said lever when moved from its normal position for preventing operation of said switch, means controlled by p a train approaching said signal for preventing return of said signal lever from its reverse posi tion beyond its normal indication position, a time element device set into operation by the return of said signal lever to its normal indication position while a train is approaching said signal, a stick relay, a pick-up circuit for said stick relay controlled by said lever and by said time element device and closed when said lever is returned to itsnormal indication position, a stick circuit for retaining said stick relay in the energized condition independently of the condition of said time element device as long as said lever,

remains in the normal indication position, and means controlled by said stick relay and by said time element device for releasing said lever and therebyrpermitting. return of said lever to its.

normal position when said time element device has been operated a measured period of time.

2. In combination, a railway track switch, a signal for governing traffic movements over said switch, manually controllable means for operating said switch, a manually operable signal lever having a normal and a reverse position and also a normal indication position, means controlled by said lever in its reverse position for clearing said signal to permit a traffic movement over said switch, means controlled by said lever when moved from its normal position for preventing operation of said switch, means controlled by a train approaching said signal for preventing return of said signal lever from its reverse position beyond its normal indication position, a time element device set into operation by the return of. said signal lever to its normal indication position while a train is approaching said signal, a stick relay, a pick-up circuit for said stick relay controlled by said lever and by said ti 1e eiement device and closed when said lever is returned to its normal indication position, a stick circuit for retaining said stick relay in the energized condition independently of the condition of said time element device as long as said lever remains in the normal indication position, means controlled by said stick relay and by said time element device for releasing said lever to permit return of said lever to its normal position when said time element device has been operated a measured period of time, and means controlled by said lever in its normal indication position for retaining said lever in its released condition independently of the condition of said stick relay or said time element device.

3. In combination, a stretch of railway track, a signal for governing traffic movements over said stretch, a second traffic governing device, manually controllable means for operating said second traffic governing device for directing traific movements over said stretch, a manually operable signal lever having a normal and a reverse position, means controlled by said lever in its reverse position for clearing said signal, means controlled by said lever when moved from its normal position for preventing operation of said second traflic governing device, means controlled by a train approaching said signal for preventing complete return of said lever to its normal position, a time element device, manually con trolled means for at times setting said time element device into operation, a stick relay, a pickup circuit for said stick relay controlled by said lever and by said time element device and closed at the time an operation of said time element device is started when said lever is returned part way to its normal position, -a stick circuit controlled by said lever for retaining said stick relay in the energized condition independently of the condition of said time element device, and means controlled by said stick relay in its energized condition and by said time element device for releasing said lever and thereby permitting complete return of said lever to its normal position when said time element device has been operated a measured period of time.

4. In combination, a stretch of railway track, a signal for governing traffic movements over said stretch, a second traflic governing device, manually controllable means for operating said second trafiic governing device for directing traiiic movements over said stretch, a manually operable signal lever having a normal and a reverse position, means controlled by said lever in its reverse position for clearing said signal, means controlled by said lever when moved from its normal position for preventing operation of said second trafiic governing device, means automatically controlled to prevent return of said lever to its normal peel-- tion, a time element device, manually controlled means for at times setting said time element device into operation, a stick relay, a pic *-up and a stick circuit for said stick relay one of which is controlled by said time element device in a first condition and the other of which is manuaily controlled independently of the condition of said time element device, and means controlled by said stick relay in its energized condition and by time element device for releasing said lever and thereby permitting return of said lever tori-ts normal position when said time element device has been operated a given measured period oi time to a second condition.

5. In combination, a plurality of railway traffic routes, a plurality of signals for governing traffic movements over said traffic routes, a manually operable control lever for each of said signals each having a normal and a reverse position, a plurality of other trafiie governing devices, manually controllable means for operating said other trafiic governing devices for directing traific movements over said routes, means controlled by each of said levers in its reverse position for clearing an associated signal, means controlled by each of said levers when moved from its normal position for preventing operation of one or more of said other trafiic governing devices or of an other of said signals, automatically operated means associated with each of said levers for at times preventing return of the associated lever to its normal position, a time element device, manually controllable means associated with each of said levers for at times setting said time element device into operation, a stick relay for each of said levers, a pick-up and a stick circuit for each of said stick relays, one of said circuits controlled by said time element device in a first condition and the other of said circuits controlled by the associated lever between its normal and reverse positions independently of the condition of said time element device, and means controlled by said time element device and by one of said stick relays for releasing the associated lever and thereby permitting return of the associated lever to its normal position when said time element device has been operated a given measured period of time after the associated stick relay became energized.

6. In combination, a plurality of railway traffic routes, a plurality of signals for governing traffic movements over said traffic routes, a manually operable control device for each of said signals, a plurality of other traffic governing devices,

,manually controllable means for operating said other trafiic governing device for directing traffic movements over said routes, means controlled by each of said control devices upon being operated for clearing, an associated signal and for preventing operation of one or more of said other traffic governing devices or of another of said signals, a time element device, manually controllable means associated with each of said manually operable control devices for at times setting said time element device into operation, a stick relay for each of said manually operable control devices, a pickup and a stick circuit for each of said stick relays one of said circuits controlled by said time element device in a first condition and the other of said circuits controlledby the associated manual- 1y operable control device independently of the condition of said time element device, and means controlled by said time element device and by each of said stick relays for releasing one or more of said other trafiic governing devices. or of said signals when said time element device has been operated from said first condition a given measured period of time after the associated stick relay became energized. 1

'7. In combination, a plurality of railway trafiic routes, a plurality of signals for governing traffic movements over'said traflic routes, a manually operable control device for each of said signals each having a normal and a reverse position, a plurality of other traffic governing devices for said routes, means controlled by each of said manually operable control devices in its reverse position for clearing an associated signal, manually controllable means for operating said other traific governing devices for directing traffic movements over said routes, a locking stick relay for each of said signals, a release stick relay for each of said locking stick relays, a time element device, manually controllable means associated with each of said release stick relays for at times setting said time element device into operation, a pick-up and a stick circuit for each of said release stick relays one of said circuits controlled by the associated manually operable control de vice in its normal position and by said time element device in its deenergized condition and the other of said circuits controlled by the associated manually operable control device in its normal position independently of the condition of said time element device until said time element device has been operated a measured period of time,

a pick-up and a stick circuit for each of said locking stick relays one of which circuits'is controlled by said time element'device and by the associated release stick relay and the other of which is controlled by the associated manually operable control device in its normal position and means controlled by each of said locking stick relays which when its locking stick relay is deenergized prevents operation of one or" said other traffic governing devices or of another signal.

8. In combination, a plurality of railway trafllc routes, a plurality of signals for governing traffic movements over said traffic routes, a manually operable control device for each of said signals, a plurality of other traific governing devices for said routes, means controlled by each of, said manually operable control devices for clearing an associated signal, manually controllable means for operating said other tra'fiic governing devices for directing traific movements over said routes,

a locking stick relay for each of said signals, a

ment device in its first condition and'the other controlled by the associated locking stick relay in the deenergized condition, a pick-up and a stick circuit for each of said locking stick relays one of which circuits is controlled by said time element device in its operatedcondition and by the 5 associated release stick relayin the energized condition and the other of which is controlled by the associated. manually operable control device,

andmeans controlled by each of said locking stick relays which when its locking stick relay is de-- energized prevents operation of one or more of signal to permit a trafiic movement over said switch, manually controllable means for operating said switch, means controlled by said device when said signal is cleared for preventing operation of said switch, means controlled by a train approaching said signal for at times preventing release of said switch by said manually controllable device, a time element device at times set into operation through the'return of said signal to the stop condition by said manually controllable device, a stick relay, a pick-up circuit for said stick relay controlled by said manually controllable device and by said time element device and closed when said manually controllable: device is returned to the condition for causing said signal to indicate stop, a stick circuit for retaining'said stick relay in the energized condition until said time element device has been operated a measured period of time, and means controlled by said time element device when operated a measured period of time and by said stick relay when energized for releasing said switch.

10. In combination, a stretch of railway track, a signal for governing trafiic movements .over said stretch, a second traffic governing device for governing trafiic movements over said stretch, a manually controllable device having a first and a second position, manually controllable means for operating said second trafiic governing device for governing traffic movements over said stretch,

means controlled by said manually controllable traffic governing device, means controlled by a.

train approaching said signal for preventing operation of said secondtrafiic governing device when said manually controllable device is returned to itsfirst position, a time'element device having a first and a second condition, manually controllable, means for at times setting said time element device into operation from its first to its second condition, a stick relay, a. pick-up circuit for said stick relay controlled by said time element device in its first condition, a stick circuit for said stick relay controlled by said manually controllable device and closed when'said manually controllable device is moved away from its second position, and means controlled by said stick relay when energized and by said time element device for releasing said second trafiic governing device when said time element device has been operated a measured period or time to its second condition.

11. In combination, a section of railway track including a switch, a signal for governing trailic movements over said switch, manually controllable means for clearing said signal, a locking stick relay, a release stick relay, a time element relay, a pick-up circuit for said locking stick relay closed by a train entering said section, a stick circuit for retaining said locking stick relay in the energized condition if said manually controllable means is notin condition for clearing said signal, a manually controllable circuit for energizing said time element relay, a pick-up circuit eifective to energize said release stick relay if said time element relay is deenergized while said locking stick relay is deenergized and said manually controllable means is not in condition for clearing said signal, a stick circuit for retaining said release stick relay energized independently of the condition of said time element relay until said locking stick relay becomes energized, a second pick-up circuit effective to energize said locking stick relay if said release stick relay is energized and if said time element relay has been energized a given measured period of time after energization of said release stick relay, and means controlled in part by said locking stick relay for operating said switch only if said locking stick relay is energized.

12. In combination, a stretch of railway track including a switch, a signal for governing traffic movements over said switch, manually controllable means operable to a control condition for clearing said signal, manually controlled switch apparatus for operating said switch, locking means operable to a locking condition by said manually controllable means for preventing operation of said switch when said manually controllable means is operated to clear said signal, a time element device, a circuit normally closed for energizing said time element device but which is opened by said locking means when said locking means is put into said locking condition, a second circuit closed by said manually controllable means for retaining said time element device in the energized condition while said manually controllable means is in said control condition, a third circuit closed by a train entering said stretch for retaining said time element device in the energized condition while said locking means is in said locking condition, release means operable to a releasing condition, a fourth circuit closed by said release means in its releasing condition for operating said time element device, means controlled by said locking means and by said time element device for operating said release means to its releasing condition if said time element device is deenergized while said locking means is in its locking condition, and means controlled by said release means in its releasing condition for restoring said locking means to its non-locking condition when said time element device has been operated a measured period of time by said fourth circuit.

13. In combination, a stretch of railway track including a switch, a signal for governing traffic movements over said switch, manually controllable means operable to a control condition for clearing said signal, manually controlled switch apparatus for operating said switch, locking means operable to a locking condition by said manually controllable means for preventing operation of said switch when said manually controllable means is operated to clear said signal, a time element device, a circuit normally closed for energizing said time element device but which is opened by said locking means when said locking means is put into said locking condition,

release means operable to a releasing condition, a second circuit closed by said release means in its releasing condition for energizing said time element device, means controlled by said locking means and by said time element device for operating said release means to its releasing condition if said time element device is deenergized while said locking means is in its locking condition, and means controlled by said release means in its releasing condition for restoring said locking means to its non-locking condition when said time element device has been energized a measured period of time.

14. In combination, a plurality of railway tracks interconnected by switches to form a plurality of trafiic routes, a plurality of signals for governing trafiic movements over said-routes, a manually controllable device for each of said signals each operable to a control condition for clearing its signal, manually controllable means for operating said switches, a locking device for each of said signals each operable to a locking condition by the manually controllable device for the associated signal for preventing operation of the switches in the route governed by the associated signal when its manually controllable device is in the control condition, a time element device, means controlled by each of said manually controllable devices when withdrawn from its control condition and by each of said locking devices when in its locking condition for setting said time element device into operation, and means controlled by said time element device and by each of said manually controllable devices when withdrawn from its control condition for releasing the associated locking device upon the lapse of a measured period of time after the beginning of the operation of said time element device.

15. In combination, a plurality of railway tracks interconnected by switches to form a plurality of trafiic routes, a plurality of signals for governing traffic movements over said routes, a manually operable lever for each of said signals each operable from a normal position to a reverse position for clearing its signal, manually controlled means for operating said switches between their extreme positions, a locking relay for each of said signals each of which becomes deenergized by operation of the lever for the associated signal to its reverse position, means controlled by each of said locking relays when deenergized for preventing operation of the switches in the route governed by the associated signal, a time element relay, means controlled by each of said signal levers when withdrawn from its reverse position and by each of said locking relays when deenergized for setting the mechanism of said time element relay into operation, and means controlled by said time element relay and by each of said signal levers when withdrawn from its reverse position for energizing the associated locking relay when said time element relay has been operated a measured period of time.

16. In combination, a plurality of railway tracks interconnected by switches to form a plurality of trafiic routes, a plurality of signals for governing trai'fic movements over said routes, a manually operable lever for each of said signals each operable from a normal position to a reverse position for clearing its signal, manually controllable means for operating said switches between their extreme positions, a normally energized locking device for each of said signals each of which becomes deenergized by operation of the lever for the associated signal to its reverse position, means controlled by each of said locking devices preventing operation of the switches in the route governed by the associated signal when the locking device is deenergized, a time element relay, a normally closed circuit for energizing said time element relay, manually operable means for opening said circuit to deenergize said time element relay and for afterward closing said circuit, and means controlled by said time element relay and by each of said signal levers when withdrawn from its reverse position for energizing the associated lockingldevice when said time element relay has again been energized a measuredperiod of time. i

17. In combination, a plurality of railway tracks interconnected by Switches to form a plurality oftrafiic routes, a plurality of signals for governing traflic movements over said routes, a manually operable lever for each of said signals each operable from a normal position to a reverse position for clearing its signal, manually controllable means for operating said switches between their extreme positions, a normally energized locking relay for each of said signals each of which becomes deenergized by operation of the lever 'for the associated signal to its reverse position, means controlled by each of said locking relays preventing operation of the switches in the route governed by the associated signal when the locking relay is deenergized, group releasing means for a given group of said locking relays comprising one time element relay for the group and. a slow release relay for each of the locking relays in the group, a circuit controlled by front contacts of said locking relays for normally energizing said time element relay, means controlled by each of said signal levers in its reverse position or by a train occupying an associated route for retaining said time element relay energized for normal train movements but causing said time element relay to be deenergized if a signal lever is withdrawn from the reverse position while a train is approaching its signal, means controlled by said time element relay upon becoming deenergized while any one of said locking relays is deenergized for energizing the associated slow release relay, means controlled by each of said slow release relays in the energized conditionfor energizing said time element relay, and means controlledflby said'time element relay and by each of said slow release relays for energizing an associatedilocking relay when said time element relay has been energized a measured period of time.

18, In combination, a plurality of railway tracks interconnected by switches to form a plurality of trafiic routes, a plurality of signals for governing traffic movements over said routes, a manually operable lever for each of said signals each operable from a normal position to a reverse position for clearing its signal, manually controllable means for operating said switches between their extreme positions, ,a normally energized locking device for each of said signals each of which becomes deenergized by operation of the lever for the associated signal to its reverse position, means controlled by each of said locking devices preventing operation of the switchesin the route governed by the associated signal when the locking device is deenergized, group releasing meansfor said locking devicescomprising one time element relay for all of said locking devices and a release relay for each of said locking devices, means controlled by each of said levers when withdrawn from its reverse position and by the associated locking device in its deenergized condition for energizing the associated release relay, manually controllable means for energizing said time 'elementrelay, and means controlled by said time element relay and by each of said release relaysfor energizing an associated locking device when said time element relay has been energized a measured period of time.

19. In combination, a plurality of railway tracks interconnected by switches to form a plurality of .traflic routes, a plurality of signals for governing traiilc movements over said routes, a manually operable lever for each of said signals 1 each operable from a normal position to a reverse position for clearing its signal, manually controllable means for operating said switches between their extremepositions, a normally energized locking devic e for each of said signals each of which becomes deenergized by operation of the lever for the associated signal to its reverse position, means controlled by each of said locking devices preventing operation of the switches in the route governed by the associated signal when the locking device is deenergized, group releasing means for said locking devices comprising one time element device for all of said locking devices and a release relay for each of saidlocking devices, means controll d by each of said levers when withdrawn from its reverse position and by said time element device when deenergized for energizing the associated release relay, manually controllable means for energizing said time element device, and means controlled by said. time element device andby each of said release relays for energizing an associated locking device when said time element device has been-energized a measured period of time. l

20. In combination, a selector relay, an electroresponsive device, a time element device,

manually controllable means for energizing said a selector relay, means preventing the selector relay from becoming energized except when the time element device has been deenergized, means effective when the selector'relay is energized to energize the time element device, and means controlled by said selector relay for energizing device contemporaneously with said selector relay, and. meanscontrolled by said selector relay for. energizing said electroresponsive device while said selector relay is energized when said time element device has been energized a measured 5 period of time.

22. In combination, a selector relay, an electroresponsive device, a time element device, a manually controllable device, means controlled by saidmanually controllable device for energizing said selector relay, means preventing the selector relay from becoming energized except when the time element device has been deenergized, a second manually controllable device, a circuit controlled by said second manually controllable device for energizing said time element device, and means controlled by said selector relay for energizing said electroresp'onsive device while said selector relay is energized when said time ele-- ment device has been energized a measured pe riod. of time.

23., Incombination, a selector relay, an electroresponsive .device, a time element device, a man- ,ually controllable device, means controlled by said manually controllable device for energizing said selector relay, means preventing the selector relay from becoming energized except when the time element device has been deenergized, means controlled by the selector relay when energized to energize the time element device, and means controlled by said time element device for energizing said electroresponsive device while said time element device is energized when the time element device has been energized a measured period of time.

24. In combination, a plurality of selector relays, an electroresponsive device for each of said selector relays, a time element device, a manually controllable device for each of said selector relays, means controlled by each of said manually controllable devices for energizing the associated selector relay, means preventing the energization of any selector relay except under the control of said time element device in its deenergized condition, means controlled by said selector relays for energizing said time element device when any one of said selector relays is energized, means controlled by an associated manually controllable device for retaining each selector relay energized while said time element device is energized, and means controlled by said time element device when it has been energized a measured period of time and by each of said selector relays in its energized condition for energizing an associated electroresponsive device.

25. In combination, a plurality of railway tracks interconnected by switches to form a plurality of trafiic routes, a plurality of signals for governing tralfic movements over said trafiic routes, a plurality of normally energized locking relays associated with said trafiic routes, manually controllable means controlled also in part by said locking relays for moving each of said switches from either of its extreme positions to the other only if given associated said locking relays are energized, manually controllable means for clearing each of said signals for permitting a traffic movement to be made over an associated route, means associated with each of said signals for deenergizing an associated said locking relay when the corresponding signal is controlled to indicate otherwise than stop, a time element device, means associated with each of said signals for energizing said time element device when the signal is again controlled toindicate stop, and means controlled by said time element device for energizing a corresponding locking relay upon the lapse of a measured period of time after each signal is controlled to indicate stop.

26. In combination, a plurality of railway tracks interconnected by switches to form a plurality of trafiic routes, a plurality of signals for governing traflic movements over said traffic routes, a plurality of normally energized locking relays associated with said tramc routes, manually controllable means controlled also in part by said locking relays for moving each of said switches from either of its extreme positions to I the other only if given associated said locking relays are energized, manually controllable means for clearing each of said signals for permitting a traffic movement to be made over an associated route, means associated with each of said signals for deenergizing an associated said locking relay when the corresponding signal is controlled to indicate otherwise than stop, a time element device, means associated with each of said signals for energizing said time element device when the signal is again controlled to indicate stop, manually operable means'for momentarily interrupting the energization of said time element device, and means controlled by said time element device for energizing one or more of said locking relays upon the lapse of a measured period of time after suchmomentary interruption of the energization of said time element device.

2'7. In combination, a plurality of railway tracks interconnected by switches to form a plurality of I trafiic routes, a plurality of signals for governing traffic movements over said traffic routes, a pmrality of normally energized locking relays associated with said traffic routes, manually controllable means controlled also in part by said locking relays for moving each of said switches from either of its extreme positions to the other only if given associated said locking relays are energized, manually controllable means for clearing each of said signals for permitting a traffic movement to be made over an associated route, means associated with each of said signals for deenergizingan associated said locking relay when the corresponding signal is controlled to indicate otherwise than stop, a normally energized time element device, means associated with each of said signals for momentarily interrupting the energization of said time element device when the signal is again controlled to indicate stop, and means controlled by said time element device for energizing one or more said locking relays upon the lapse of a measured period of time after such momentary interruption of the energization of said time element device.

28. In combination, a plurality of railway tracks interconnected by switches to form a plurality of trafic routes, a plurality of signals for governing trafiic movements over said traflic routes, a plurality of manually operable signal levers each having a, normal position and one or more reverse i positions, an electric lever lock for each of said signal levers which if deenergized prevents movement of its lever from a reverse position to the normal position, manually controllable means for moving each of said switches from either of its v extreme positions to the other only if given said signal levers are in the normal position, means controlled by each of said signal levers when moved to a reverse position for clearing an associated signal, a time element device, means controlled by each of said signal levers for energizing said time element device when an attempt is made to return the signal lever from a reverse position to its normal position, and means controlled by said time element device for energizing one or stick relays controlled by given trafilc conditions for energizing the corresponding stick relay if a signal for the same route is controlled to indicate stop, a stick circuit for each of said stick relays for retaining the corresponding stick relay in its energized condition independently of said given trafiic conditions as long as a signal for the same route is controlled to indicate stop, group control apparatus for said stick relays comprising a manually controllable time releasing device as well as a plurality of slow release relays one for each of said parallel routes, means controlled by said time releasing device in a given initial condition for energizing each of said slow release relays, a retaining circuit for each "of said slow release relays'for retaining its slow release relay in the energized condition while the stick relay for the same route remains deenergized, means controlled by said time element device and by each or said slow release relays for energizing the stick relay ,for the same route after said time element device has been operated away from said given initial condition for'a measured period of time, manually controllable apparatus controlled in part by said stick relays for operating said switches, and manually controllable means for clearing said signals and for controlling said signals to indicate stop.

30. In combination, a pluralityof parallel railwaytrafiic routes interconnected by switchesand provided with signals for governing trafiic movements over said routes, a stick relay for each of said routes, a pick-upcircuit for each of said stick relays controlled by given traffic conditions, a stick 'circuit for each of said stick relays for retaining the corresponding stick relay in its energized condition as long as a signal for the same route is controlled to indicate stop, group control apparatus for said stick relays comprising a manually controllable time element device'as well as a plurality of slow release relays one for each of said parallel routes, means controlled'by said time element device in a given initial condition for energizing each of said slow release relays, a retaining circuit for each of said slow release relays for retaining its slow release relay in the energized conditionwhile the stick relay for the same route remains deenergized, means controlled by said time element device and by each of said slow release relays for energizing the' stick relay for the same route after said time element device has been operated away from said given initial condition for a measured period of time, manually controllable apparatus controlled in part by said stick relays for operating said switches, and manually controllable means for at times clearing said signals.

31. In combination, a plurality of parallel railway traffic routes interconnected by switches and provided with signals for governing trafiic movements over said routes, switch locking apparatus for each of said routes operable from a second to a first condition under control by given trafilc conditions, manually controllable apparatus for operating each of said switches, means controlled by the switch locking apparatus for each route to permit operation of a corresponding switch when said switch locking apparatus is in said first condition but to prevent operation of the corresponding switch when said switch locking apparatus is in its second condition, group control apparatus for said switch locking apparatus comprising a manually controllable time element device as well as a plurality of stick relays one for each of said parallel routes, means controlled by said time element device in a given initial condition for energizing each of said stick relays, a stick circuit for each of said stick relays for retaining its stick relay in the energized condition while a signal for the same route is controlled to indicate stop, means controlledby said time element device' and by each of said stick relays for operating the switch locking apparatus for the corresponding route to said first condition independently of said given trafiic conditions when said time element device has been operated away from said given initial condition for almeasured period of time, and manually controllable means for at times clearing said signals.

32. In combination, stick locking apparatus'for a plurality of parallel railway trafllc routes each of which is provided with switches and with signals for governing traflic movements in both directions, said stick locking apparatus comprising a stick locking relay for each direction of trafiic movement over each of the parallel routes and a pick-up circuit for each of said stick locking relays which is closed by the entrance of a train t into the associated trafiic route as well as a stick circuit for each of said stick locking relays controlled in conjunction with an associated signal for retaining its stick locking relay in the energized condition as long as the associated signal continues to indicate stop, group releasing ap paratus for said stick locking apparatus comprising a manually controllable time releasing device as well as a plurality of slow release relays each controlled by thetime releasing device to become energized if one of the stick locking relays is deenergized and also means controlled by said slow release relays and-by said time releasing device for energizing each of said stick locking of time after an associated signal ha's'been controlled to indicate stop, manually controllable switch operating apparatus for said switches controlled in part by said stick locking relays, and manually controllable means for at times clear ing said signals. a

33. In combination, stick locking apparatus for a plurality of parallel railway trafiic routes each of which includes one or more switches and is provided with signals for governing traiiic movements in both directions, said stick locking apparatus comprising a stick locking relay for each direction of trafiic movement over each of the parallel routes and means for energizing each of said stick locking relays under given traffic conditions as well as means for retaining each of said stick locking relays in the energized condition as long as an associated signal is controlled to indicate stop, i

group control apparatus for said stick locking relays comprising a manually controllable time element device and a plurality of locking release relays, means controlled by said time element device in a given initial condition for energizing r each of said locking release relays, means controlled in conjunction with said signals for retaining each of said lockinglrelease relays in the energized condition while an associated signal is controlled to indicate stop, means controlled by said time element device and by a corresponding locking release relay for energizing each of said locking stick relays when said time elementdevice has been operated away from said initial condition a measured period of time, manually controllable apparatus controlled in part by said stick locking relays for operating said switches, and manually controllable means for at times clearing said signals.

34. In combination, a pluralityof parallel railrelays upon the lapse of a given minimum period dependently of said given trafliic conditions as long as an associated signal continues to indicate stop, group releasing apparatus for said switch locking apparatus comprising a manually controllable time releasing device as well as a plurality of slow release relays each of which is controlled by the time releasing device and also means controlled by each of said slow release relays for energizing each of said stick relays upon the lapse of a given minimum period of time after the associated signal has been controlled to indicate stop, manually controllable apparatus controlled in part by said switch locking apparatus for operating said switches, and manually controllable means for at times clearing said signals.

35. In combination, a plurality of parallel railway trafiic routes each of which is provided with one or more switches and with a signal for governing trafiic movements through the route, switch locking apparatus for said routes comprising a stick relay for each of the parallel routes and means controlled by given traffic conditions for energizing each of said stick relays if an associated signal indicates stop as well as means for retaining each of said stick relays in its energized condition independently of said given trafiic conditions as long as an associated signal continues to indicate stop, group releasing apparatus for said switch locking apparatus comprising a manually controllable time releasing device as well as a plurality of locking release relays controlled by the time releasing device and by back contacts of corresponding said stick relays and also means controlled by said locking release relays and by said time releasing device for energizing each of said stick relays upon the lapse of a given minimum period of time after an associated signal has been controlled to indicate stop, manually controllable apparatus controlledin part by said stick relays for operating said switches, and manually controllable means for clearing said signals.

CHARLES W. BELL. 

